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diff --git a/manual/probes.texi b/manual/probes.texi new file mode 100644 index 0000000000..fc02ffddc9 --- /dev/null +++ b/manual/probes.texi @@ -0,0 +1,41 @@ +@node Internal Probes +@c @node Internal Probes, , POSIX Threads, Top +@c %MENU% Probes to monitor libc internal behavior +@chapter Internal probes + +In order to aid in debugging and monitoring internal behavior, +@theglibc{} exposes nearly-zero-overhead SystemTap probes marked with +the @code{libc} provider. + +These probes are not part of the @glibcadj{} stable ABI, and they are +subject to change or removal across releases. Our only promise with +regard to them is that, if we find a need to remove or modify the +arguments of a probe, the modified probe will have a different name, so +that program monitors relying on the old probe will not get unexpected +arguments. + +@menu +* Memory Allocation Probes:: Probes in the memory allocation subsystem +@end menu + +@node Memory Allocation Probes +@section Memory Allocation Probes + +These probes are designed to signal relatively unusual situations within +the virtual memory subsystem of @theglibc{}. + +@deftp Probe memory_arena_new (void *@var{$arg1}, size_t @var{$arg2}) +This probe is triggered when @code{malloc} allocates and initializes an +additional arena (not the main arena), but before the arena is assigned +to the running thread or inserted into the internal linked list of +arenas. The arena's @code{malloc_state} internal data structure is +located at @var{$arg1}, within a newly-allocated heap big enough to hold +at least @var{$arg2} bytes. +@end deftp + +@deftp Probe memory_mallopt (int @var{$arg1}, int @var{$arg2}) +This probe is triggered when function @code{mallopt} is called to change +@code{malloc} internal configuration parameters, before any change to +the parameters is made. The arguments @var{$arg1} and @var{$arg2} are +the ones passed to the @code{mallopt} function. +@end deftp |